LMN/NOPB Texas Instruments Audio Amplifiers 5-W AUDIO POWER AMP datasheet, inventory, & pricing. LMN Datasheet, LMN National Semiconductor 5-Watt Audio Amplifier Datasheet, buy LMN. The LM is a power audio amplifier for consumer applica- tion In order to hold system cost to a minimum gain is internally fixed at 34 dB A unique input stage.

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Probably the most interesting thing to look at is the input stages. The suggested heatsink designs are shown below. Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. The impedance at both inputs is 50k, set by internal resistors.

Note datasheer you cannot use aluminium because it can’t be soldered, but you dagasheet be able to use small copper tabs that are rivetted to an aluminium heatsink with heatsink compound between the two metals.

While it looks very similar to the LM circuit shown above, note that the pin numbers are different.

5-W Audio Power Amplifier

It’s important to understand that the LM is not an opamp, and none of the traditional lm348n circuits can be applied. I don’t think I even need to say that this IC isn’t suitable for a subwoofer. A copper lead frame is used with the center three pins on either side comprising a heat sink. See SNAA for circuit details. The only thing that even approaches being critical is the bypass cap.

Commercial use is prohibited without express written authorisation from Rod Elliott.

While a PCB would be handy, the cost datasueet the board would be greater than the cost of the IC and other parts and it’s not worthwhile. Feel free to include a nF multilayer ceramic bypass cap as close to the supply pins as possible it’s not darasheet in the above drawings. This makes the device easy to use in standard p-c layout.

The load impedance needed is higher daatasheet any small speakers you can get, ratasheet you simply don’t build an amp using an LM if you need more than a few milliwatts.


It would be worthwhile to give it a very light spray with matte black paint to improve radiation. The output automatically self-centers to one-half the. A copper lead frame is used with the center three. The package outline is standard dual-in-line. C5 is a supply bypass cap, and it should be as close to the supply pins as possible.

The IC is useful for headphones, intercoms, portable radios etc. The LM is also available in a pin package, which has greater dissipation and can provide more power.

The circuit is shown for reference only, and is adapted from the datasheet but has been redrawn. A unique input stage allows ground referenced input signals. If these pins are linked datashdet a 10uF capacitor, the gain is 46dB. The author Rod Elliott grants the reader the right to use this information for personal use only, and further allows that one 1 copy may be made for reference while constructing the project.

It’s theoretically possible if you use a high supply voltage and a 16 or 32 datasheeh load, but that’s not recommended because device dissipation will be well in excess of that which the device can handle safely.

In order to hold system cost to a.

It’s worth mentioning that the above circuit can be simulated and will give the expected results, but you need to replace the upper NPN output transistor Q7 with a Darlington pair datasbeet you will not get symmetrical clipping. That means that the maximum input voltage will be around mV RMS sinewave at the onset of clipping. Maximum output power into an 8 ohm load is around mW for acceptable distortion.

None are anything special, and they are fairly low power the LM is only rated for mW into 8 ohms.

The output automatically self-centers to one-half the supply voltage. Two are needed, one for each side of the IC. However, the performance is such that I doubt it would meet the required standards for professional use, and I have never seen an LM used in pro gear. Production processing does not necessarily include testing of all parameters. It should be easy enough to fabricate a suitable heatsink if you have some sheet copper available.


Reproduction or re-publication by any means whatsoever, whether electronic, mechanical or electro-mechanical, is strictly prohibited under International Copyright laws.

It usually won’t need to be anything special, but it will usually have to be cheap and easy to build. Construction of any of these amps is non-critical, and Veroboard or similar is the way that most people would build one. Of the three types, the LM is the more popular. If you want to know more, have a look at the datasheets. In order to hold system cost to a minimum, gain is internally fixed at 34 dB.

5-W Audio Power Amplifier

For best thermal performance, the heatsink s should be soldered directly to the pins, and ideally will also have a good thermal bond with the top of the IC package. Products conform to specifications per the terms of the Texas Instruments standard warranty. The gain can be changed by adding a capacitor between pins 1 and 8.

Uses range from signal tracers, workshop monitor amps to listen to distortion residuals for exampleor just a simple project for the fun of it. However, that varies with supply voltage and load impedance so you’ll need to assess the circuit under your operating conditions.

The quiescent output voltage is set internally to be half the supply voltage, and by default the gain is 20 26dB.

LM from Texas Instruments

The supply voltage needs to be no more than 12V and the load impedance should not be less than 8 ohms. The bypass cap C2 is optional as well, but if you don’t include it the power supply rejection is rather poor, so anything other than a battery supply may cause some hum.

Add a resistor and capacitor in series between pins 1 and 8 for intermediate gains.